Ski binding

ABSTRACT

Ski binding having progressively diminishing release force. A ski binding component, such as a plate intermediate the ski boot and the ski, is held releasably in normal operating or boot holding position by means so arranged that the force which must be overcome to effect release thereof will progressively diminish as such component moves out of said normal position. In the illustrated embodiment this is accomplished by providing a pair of simultaneously operating rocking levers wherein pivotal rocking movement thereof occurs upon application of a force thereto and resistance to said force is provided by resilient means. The parts are so arranged that as the release force is applied the effective lever arm of the applied force will progressively lengthen and the lever arm of the resisting force will progressively shorten, whereby to progressively diminish the force which must be overcome to effect release. In the illustrated embodiment the rocking levers are provided by a single eccentric around which is wrapped a cable with one end thereof being connected to boot engaging means and the other thereof being connected to a resisting spring. Movement of the boot out of normal position pulls the cable to cause rotative movement of the eccentric around its pivot point and thereby the change in effective lever arms as above described.

United States Patent [1 1 Schweizer [451 Dec. 9, 1975 SKI BINDING [75] Inventor: Gottfried Schweizer, Vienna,

Austria [73] Assignee: Gertsch AG, Zug, Switzerland [22] Filed: June 3, 1974 [21] Appl. No.: 475,755

[30] Foreign Application Priority Data Primary ExaminerLeo Friaglia Assistant Examiner-Milton L. Smith Attorney, Agent, or Firm-Woodhams, Blanchard and Flynn [57 ABSTRACT Ski binding having progressively diminishing release force. A ski binding component, such as a plate intermediate the ski boot and the ski, is held releasably in normal operating or boot holdling position by means so arranged that the force which must be overcome to effect release thereof will progressively diminish as such component moves out of said normal position. In the illustrated embodiment this is accomplished by providing a pair of simultaneously operating rocking levers wherein pivotal rocking movement thereof occurs upon application of a force thereto and resistance to said force is provided by resilient means. The parts are so arranged that as the release force is applied the effective lever arm of the applied force will progressively lengthen and the lever arm of the resisting force will progressively shorten, whereby to progressively diminish the force which must be overcome to effect release. In the illustrated embodiment the rocking levers are provided by a single eccentric around which is wrapped a cable with one end thereof being connected to boot engaging means and the other thereof being connected to a resisting spring. Movement of the boot out of normal position pulls the cable to cause rotative movement of the eccentric around its pivot point and thereby the change in effective lever arms as above described.

11 Claims, 10 Drawing Figures l l l l l l 19 24 I7 73 I5 I3 12 I4 US. Patent Dec. 9, 1975 Sheet 2 of 5 I U..S. Patent Dec. 9, 1975 Sheet 3 of5 3,924,866

U.S. Patent Dec. 9, 1975 Sheet 4 of5 3,924,866

ADJUSTING DEVICE SKI BINDING FIELD OF THE INVENTION The invention relates to a ski binding having a sole holding part which is mounted on the ski for movement against the force of at least one spring.

BACKGROUND OF THE INVENTION In one previously known construction, fittings are provided on the ski boot which are pulled by cables to abutments which are mounted on the ski. Each cable end is anchored in a cable drum which is acted on by at least two springs. A relatively weak spiral spring is provided within the cable drum, a further spring which exsharply because then the pin is only urged against the peripheral surface of the cable drum and thus only the force of the relatively weak spring within the cable drum needs to be overcome together with, of course, the corresponding frictional forces.

As in all known bindings, the force here progressively increases during the release. In practice, however, it is required that the holding force during use is at maximum and when same is overcome during a release operation it is reduced. Further, in the known devices, very large frictional forces occur at the engaging or locking parts. Thus, there is at present the danger that injuries can occur because the increase in applied force during a release creates stresses which are too great for the parts of the body. Attempts have been made to find a middle way, namely, by reducing the initial holding force. This, however, has again the disadvantage that the boot can easily loosen relative to the ski and thus adversely affect the control over the ski.

SUMMARY OF THE INVENTION The purpose of the invention is to produce a ski binding in which the force which must be overcome during a release operation diminishes from the start thereof. This objective is achieved by connecting the sole holding part to a rotatably supported transmitting part through a traction cable, to which transmitting part a spring is also connected, and providing that the normal distance of the line of force exerted by the spring and- /or the normal distance of the traction cable from the axis of rotation of the transmitting part changes during the rotation of said transmitting part.

This, in spite of an increasing tension of the spring, results in reducing the force which must be overcome, because by changing the normal distance of the lines of force exerted the lever relationships are also changed. Thus, it is possible to either reduce the normal distance of the spring force or it is possible to enlarge the normal distance of the cable line or both normal distances may change simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS The subject matter of the invention is illustrated in the form of several exemplary embodiments in the drawings, in which:

FIG. 1 illustrates a force schematic as utilized in the invention with a double-arm lever,

.FIG. 2 illustrates a spring diagram,

FIGS. 3 and 4 are associated views of one embodiment of the invention wherein FIG. 3 is a cross-sectional view along the line III-III of FIG. 4 and FIG. 4 is a cross-sectional view along the line IV-IV of FIG.

FIGS. 5 and 6 are also associated views of the same embodiment with the heel being lifted, wherein FIG. 5 is a cross-sectional view along the line V-V of FIG. 6 and FIG. 6 is a cross-sectional view along the line VI-VI of FIG. 5,

FIG. 7 is also a cross-sectional view along the line IVIV of FIG. 3, however, with the tip of the sole holder part being pivoted away from its normal operation position,

FIG. 8 is a schematic illustration of a modified embodiment of the invention having a single force transmitting part;

FIG. 9 is a modified double-arm lever having an adjustment mechanism for varying the relative position of the arms; and

FIG. 10 is a modified cable pulley having an adjustment mechanism for varying the angular relationship therebetween.

DETAILED DESCRIPTION In the schematic of FIG. 1 a two-arm lever 1, 2 is supported pivotally about an axis of rotation 3. A spring force F is applied to the end of the lever arm 1, which spring force has a normal radius a from the axis of rotation 3. A force P is exerted at a normal distance b on the lever arm 2 in the equilibrium state. If now the lever 1, 2 is pivoted, for example into the position which is illustrated in dash-dotted lines, then a greater spring force F is created, which, however, has a substantially smaller normal distance a from the axis of rotation 3. The lever arm 2 has increased its normal distance from 12 to b whereby the force P which is necessary for the equilibrium may now be substantially smaller than the force P From this it is evident that in spite of an increasing spring force corresponding to the angle of traverse the reaction force becomes continuously smaller.

The diagram of FIG. 2 shows the forces occurring during a release operation in a known device and in the device of the invention. The release motion 5 is entered on the horizontal axis and the release force P on the vertical axis. The dashed line 4 shows the force characteristics of a known release mechanism, such as the one chosen for the example described above. During the release, the release force constantly increases, corresponding to the increasing spring force. After a certain point has been reached, the release occurs and this causes the force to drop off either to zero or if a second, substantially weaker spring then acts, the force drops to a substantially lower value, from which, again, there occurs a small force increase corresponding to the stiffness of the weaker spring.

The force changes which occur during a release operation of a binding according to the invention are represented by the full line 5. Here the spring force is modified so that the release force progressively diminishes along the release pattern. Of course, the spring force can be modified in such a manner that in place of a falling straight line, a falling curve may alternatively be followed.

As shown in FIGS. 3 to 7, the ski boot is held on a sole plate 6 by means of a front stop 7 and a heel fastening means 8. Two traction cables 9 and 10 are anchored at their ends on the sole plate 6. They extend through guides 11, 12 into the housing 13 which is secured on the ski 14. The other ends of the traction cables are anchored on transmitting parts 15, 16 which here comprise eccentrics arranged pivotally about axes of rotation 17, 18 in the housing 13. The extended ends 19, 20 of the tension springs 21, 22 are also connected to the transmitting parts 15, 16.

The transmitting parts 15, 16 form each two cable pulleys 23, 24, 25, 26 whose peripheries comprise .curves with respect to the axes of rotation 17, 18. The

extended ends 19, 20 of the springs 21, 22 and the ends of the traction cables 9, 10 which are secured on the transmitting parts 15, 16 are arranged for winding onto and off the curve-shaped cable pulleys 23, 24, 25, 26. The tension of the springs 21, 22 can be varied by means of the screws 27, 28 which are arranged in the housing 13 and which are engaged by the spring ends.

Upon occurrence of an overload, for example during a fall forwardly, the rear area of the sole plate 6 will lift off the ski boot, whereby the traction cable 10 is pulled out against the force of the spring 21. The transmitting part rotates about the axis 17 so that the extended end 19 of the spring 21 is wound onto the cable pulley 23 and the traction cable 10 is wound off the cable pulley 24. As the spring 21 is tensioned, however, the normal distance of the line of force of the spring 21 from the axis of rotation 17 of the transmitting part is reduced. In the same manner, however, the normal distance of the line of force of the traction cable is increased. Due to the cam shapes of the cable pulleys 23, 24, the lever relationships are so changed here too that the force which must be applied is reduced the farther the traction cable 10 is pulled out. This means in other words, the lever relationships change as described above in connection with FIG. 1.

If a lateral overload occurs, the sole plate 6 swings to one side, whereby, as can be recognized in FIG. 7, the traction cable 9 is pulled from the transmitting part 16. Such swinging takes place around an upwardly projecting shoulder 29 (FIG. 3) which is formed on the housing 13 and which projects into a correspondingly fitting recess 30 of the sole plate 6. Here too the force of the spring 22 is modified in the same manner in that the extended end 20 of the spring 22 is rolled onto the cable pulley 25 and the traction cable 9 rolls off the cable pulley 26. Hence, again, by changing the lever relationships the farther the traction cable 9 is pulled out the smaller becomes the pull thereon.

Of course, during a so-called diagonal fall, for example, both traction cables 9, 10 are pulled from their associated transmitting parts 15, 16. However, there always exists through the spring force a force tending to hold the ski boot or the sole plate 6 on the ski so that after a fall when the ski boot has slightly moved from the ski, same is pulled back automatically into the original position, as same is particularly illustrated in FIG. 3. In order to limit the rotational movement of the transmitting parts 15, 16, these carry at their outer periphery ears 31, 32 with which limiting stops 33, 34, 35, 36,

which are secured in the housing 13, are associated in each direction of movement.

The invention is not limited to the illustrated exemplary embodiments. A number of further possibilities exist which lie within the scope of the invention. In the illustrated inventive construction, one transmitting part would also be sufficient by connecting both traction cables on this one transmitting part (FIG. 8). It would also be possible to provide a traction cable according to the invention with spring-loaded transmitting parts in front of and behind the ski boot, whereby the end of each traction cable may be secured directly onto the ski boot or onto a fitting. Further, it is essential to pro vide at least one, but only one, of the cable pulleys eccentrieally or curved with respect to the pivot point on each transmitting part. The other one can be positioned concentrically to the pivot point. Furthermore one or both cable pulleys can be arranged adjustably and fixably on the transmitting part (FIGS. 9 and 10).

Although particular preferred embodiments of the invention have been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof which lie within the scope of the appended claims are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A ski binding arrangement for holding a ski boot onto a ski, comprising:

a mounting plate having fastening means thereon for fastening said ski boot to said mounting plate; threshold releasing securement means for securing said mountingplate to said ski, said threshold releasing securement means including force transmitting means mounted on one of said mounting plate and said ski and pivotal about a fixed pivot axis,

elongated cable means secured at one end to said force transmitting means and engaging said force transmitting means at a first location thereon and at the other end to the other of said ski and said mounting plate and resilient means connected at one end to said force transmitting means and applying a force thereto at a second location thereon and anchored at the other end to said one of said mounting plate and said ski, said resilient means effecting a tensioning of said cable means through said force transmitting means to define a holding force when said mounting plate is mounted on said ski and the longitudinal axis of said mounting plate is parallel to said longitudinal axis of said ski;

a first normal spacing between a longitudinal axis of said cable means adjacent and extending away from said force transmitting means and intersecting said first location and said pivot axis being less than a second normal spacing between a longitudinal axis of said resilient means adjacent and extending away from said force transmitting means and intersecting said second location and said pivot axis while said mounting plate is mounted on said ski and the longitudinal axis of said mounting plate is parallel to said longitudinal axis of said ski, said first normal spacing increasing and said second normal spacing decreasing and said resilient means becoming more tensioned and said cable means becoming less tcnsioned in response to an increasing movement of any part of said mounting plate away from said ski. an initial movement of said mounting plate being resisted by said holding force and upon an exceeding of said holding force, a release of said mounting plate from engagement with said ski will be effected.

2. A ski binding according to claim 1, wherein said force transmitting means is defined by a two-arm lever and wherein said resilient means comprises a spring pivotally connected to the one arm and said cable means is connected to the other arm.

3. A ski binding according to claim 2, wherein said two-arm lever has a general L-shape.

4. A ski binding according to claim 1, wherein said force transmitting means includes two fixed together cable pulleys, said cable means engaging one of said pulleys at said first location, said resilient means applying a force to the other of said pulleys at said second location and wherein at least one of said cable pulleys is arranged eccentrically to said pivot axis.

5. A ski binding according to claim 4, wherein both of said cable pulleys are arranged eccentrically to said pivot axis.

6. A ski binding according to claim 1, wherein said mounting plate is connected to said ski through a pair of said threshold releasing securement means.

7. A ski binding according to claim 1, wherein said mounting plate is connected to the ski through two cable means which engage on one common force transmitting means.

8. A ski binding according to claim 1, including adjustment means for adjusting said first and second spacing relative to said pivot axis.

9. A ski binding according to claim 1, wherein said first and second locations are located at all times on opposite sides of a theoretical vertical plane extending parallel to the longitudinal axis of said ski and containing said pivot axis.

10. A ski binding according to claim 1, wherein said first and second locations are located at all times on the same side of a theoretical vertical plane extending parallel to the longitudinal axis of said ski and containing said pivot axis.

11. A ski binding according to claim 1, wherein said force transmitting means is pivotally secured to said mounting plate and said cable means is secured at said other end to said ski and said other end of said resilient means is anchored to said mounting plate. 

1. A ski binding arrangement for holding a ski boot onto a ski, comprising: a mounting plate having fastening means thereon for fastening said ski boot to said mounting plate; threshold releasing securement means for securing said mounting plate to said ski, said threshold releasing securement means including force transmitting means mounted on one of said mounting plate and said ski and pivotal about a fixed pivot axis, elongated cable means secured at one end to said force transmitting means and engaging said force transmitting means at a first location thereon and at the other end to the other of said ski and said mounting plate and resilient means connected at one end to said force transmitting means and applying a force thereto at a second location thereon and anchored at the other end to said one of said mounting plate and said ski, said resilient means effecting a tensioning of said cable means through said force transmitting means to define a holding force when said mounting plate is mounted on said ski and the longitudinal axis of said mounting plate is parallel to said longitudinal axis of said ski; a first normal spacing between a longitudinal axis of said cable means adjacent and extending away from said force transmitting means and intersecting said first location and said pivot axis being less than a second normal spacing between a longitudinal axis of said resilient means adjacent and extending away from said force transmitting means and intersecting said second location and said pivot axis while said mounting plate is mounted on said ski and the longitudinal axis of said mounting plate is parallel to said longitudinal axis of said ski, said first normal spacing increasing and said second normal spacing decreasing and said resilient means becoming more tensioned and said cable means becoming less tensioned in response to an increasing movement of any part of said mounting plate away from said ski, an initial movement of said mounting plate being resisted by said holding force and upon an exceeding of said holding force, a release of said mounting plate from engagement with said ski will be effected.
 2. A ski binding according to claim 1, wherein said force transmitting means is defined by a two-arm lever and wherein said resilient means comprises a spring pivotally connected to the one arm and said cable means is connected to the other arm.
 3. A ski binding according to claim 2, wherein said two-arm lever has a general L-shape.
 4. A ski binding according to claim 1, wherein said force transmitting means includes two fixed together cable pulleys, said cable means engaging one of said pulleys at said first location, said resilient means applying a force To the other of said pulleys at said second location and wherein at least one of said cable pulleys is arranged eccentrically to said pivot axis.
 5. A ski binding according to claim 4, wherein both of said cable pulleys are arranged eccentrically to said pivot axis.
 6. A ski binding according to claim 1, wherein said mounting plate is connected to said ski through a pair of said threshold releasing securement means.
 7. A ski binding according to claim 1, wherein said mounting plate is connected to the ski through two cable means which engage on one common force transmitting means.
 8. A ski binding according to claim 1, including adjustment means for adjusting said first and second spacing relative to said pivot axis.
 9. A ski binding according to claim 1, wherein said first and second locations are located at all times on opposite sides of a theoretical vertical plane extending parallel to the longitudinal axis of said ski and containing said pivot axis.
 10. A ski binding according to claim 1, wherein said first and second locations are located at all times on the same side of a theoretical vertical plane extending parallel to the longitudinal axis of said ski and containing said pivot axis.
 11. A ski binding according to claim 1, wherein said force transmitting means is pivotally secured to said mounting plate and said cable means is secured at said other end to said ski and said other end of said resilient means is anchored to said mounting plate. 